685509044 has 18 divisors (see below), whose sum is σ = 1318614402. Its totient is φ = 311594800.

The previous prime is 685509029. The next prime is 685509073. The reversal of 685509044 is 440905586.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 554131600 + 131377444 = 23540^2 + 11462^2 .

It is a junction number, because it is equal to n+sod(n) for n = 685508992 and 685509010.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 707687 + ... + 708654.

Almost surely, 2^685509044 is an apocalyptic number.

It is an amenable number.

685509044 is a deficient number, since it is larger than the sum of its proper divisors (633105358).

685509044 is a wasteful number, since it uses less digits than its factorization.

685509044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416367 (or 1416354 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 41.

The square root of 685509044 is about 26182.2276363185. The cubic root of 685509044 is about 881.7342881840.

The spelling of 685509044 in words is "six hundred eighty-five million, five hundred nine thousand, forty-four".